Dialysis-Related Disorders (Complications of Dialysis)

Why complications happen

Dialysis replaces only part of what healthy kidneys do. It removes waste, extra fluid and salts in sessions, not continuously, and it does not fully replace kidney hormones. Rapid shifts in fluid and chemicals during treatment, the need for repeated access to the bloodstream, and the underlying effects of kidney failure all contribute to complications.

Complications during hemodialysis

Vascular access problems

• Fistula or graft clotting: losing the buzz (thrill) over the access is an urgent problem. Prompt treatment can often reopen it.
• Narrowing (stenosis): causes poor flow, prolonged bleeding after needles, or arm swelling.
• Infection: especially with central venous catheters. Bloodstream infections can spread to the heart valves (endocarditis) or bones.
• Aneurysms of the fistula, and rarely bleeding.
• Steal syndrome: the access diverts blood from the hand, causing cold, painful or numb fingers.

Peritoneal dialysis complications

• Peritonitis: infection of the belly lining, causing cloudy drained fluid, belly pain and fever. It needs prompt antibiotics, usually added to the dialysis fluid.
• Exit-site and tunnel infections around the catheter.
• Catheter problems: poor drainage from blockage or displacement, often linked to constipation.
• Hernias and fluid leaks from increased pressure in the belly.
• Weight gain and high blood sugar from glucose in the dialysis fluid.
• Long-term membrane changes that reduce dialysis effectiveness.

Long-term complications of dialysis and kidney failure

• Fluid overload: too much fluid between sessions causes swelling, high blood pressure and fluid on the lungs.
• High potassium (hyperkalemia): especially after missed sessions or high-potassium foods. It can cause dangerous heart rhythms with few warning signs.
• Anemia: the kidneys make less erythropoietin. Treated with iron and erythropoiesis-stimulating agents.
• Bone and mineral disorder: high phosphate, low calcium and secondary hyperparathyroidism weaken bones and calcify blood vessels. Managed with phosphate binders, diet, vitamin D and medicines that lower parathyroid hormone.
• Heart disease: the leading cause of death in people on dialysis.
• Dialysis-related amyloidosis: after many years, deposits of beta-2 microglobulin can cause carpal tunnel syndrome and joint pain.
• Itching (uremic pruritus): common and distressing, linked to phosphate and other factors.
• Restless legs and sleep problems.
• Fatigue, depression and anxiety.
• Malnutrition and muscle loss.
• Infections, including hepatitis B, which is why vaccination is recommended.

How complications are monitored

Your dialysis team checks weight, blood pressure and the access at every session. Monthly blood tests usually include potassium, phosphate, calcium, hemoglobin, albumin, parathyroid hormone and measures of how well dialysis is clearing waste (Kt/V). The access is examined regularly, and ultrasound is used if flow drops.

Prevention and self-care

• Attend every full session. Missing or shortening sessions is a major cause of high potassium and fluid overload.
• Follow fluid limits: your team will set a daily allowance. Aim to keep weight gain between hemodialysis sessions within the target your team gives you.
• Limit salt, which drives thirst.
• Follow your potassium and phosphate diet, and take phosphate binders with meals as prescribed.
• Protect your access: no blood pressure cuffs, blood draws, tight clothing or sleeping on the fistula arm. Check the thrill daily. Keep catheters dry and covered.
• Wash hands and follow sterile technique for peritoneal dialysis exchanges.
• Get vaccinated against hepatitis B, flu, COVID-19 and pneumococcus.
• Report symptoms early, including low mood and itching, which can be treated.

Frequently asked questions

What are the most common side effects of dialysis?

During hemodialysis, low blood pressure and muscle cramps are the most common, along with nausea, headache and tiredness after sessions. Peritoneal dialysis most often causes catheter infections and peritonitis. Over time, itching, fatigue, anemia, bone problems and fluid overload are common.

Why does blood pressure drop during dialysis?

Blood pressure drops when fluid is removed from the blood faster than the body can refill the blood vessels from the tissues. Large weight gains between sessions, blood pressure medicines taken before dialysis and heart problems make it more likely. Limiting fluid intake helps most.

What happens if you miss a dialysis session?

Waste, fluid and potassium build up. This can cause swelling, breathlessness, high blood pressure and dangerously high potassium, which can affect the heart rhythm without warning. Contact your dialysis unit the same day to reschedule, and seek emergency care for chest pain, breathlessness or weakness.

What are the signs of a dialysis access infection?

Signs include redness, warmth, swelling, pain or pus at the fistula, graft or catheter site, and fever or chills, especially during or after dialysis. With peritoneal dialysis, cloudy drained fluid and belly pain suggest peritonitis. Infections need prompt treatment.